Flash crash or a turning point for oil prices?

By John Kemp – Monday’s (Sep 17) sudden dive in oil prices appears more and more unusual with hindsight, and poses questions for traders, regulators and exchanges alike about just who or what caused such a major turnaround in the market.

Explanations range from a “fat finger” trading error or a high-frequency computer trading program run amok to a concentration of stop-loss orders being triggered or a single large trade by a hedge fund selling up to 10 million barrels of crude in a single clip, though no one appears to know for certain.